Using ablation technology to treat human tissue is currently known in the art. Ablation technology, such as radiofrequency (RF), microwave, and irreversible electroporation (IRE)—including thermal IRE and non-thermal IRE—are well-known for their applicability in treatment, coagulation and/or targeted ablation or treatment of tissue in the human body. During procedures using such technology, a treatment probe, commonly either an electrode or antenna, is typically advanced into the patient laproscopically, percutaneously or through an open surgical incision until the target tissue is reached. Once properly positioned at the target site, energy is transferred to the probe. The type, amount, and range of energy delivered to the probe varies and depends on the specific treatment modality. During transmission of treatment energy to the target tissue, the outer surface of the probe and/or the cables transmitting the energy may reach high temperatures specifically when the treatment energy is in the form of either RF or microwave energy. When exposed to such elevated temperatures, the treatment site, as well as the surrounding tissue, may be unintentionally heated beyond the desired treatment parameters or treatment zone. Cooling fluid may be circulated through the ablation system to remove excess heat from the probe and/or cable, prevent device malfunctioning and/or avoid unintended harm to the user or patient. To remove excess heat generated by the system, the cooling fluid may be circulated through the ablation system. Commonly, peristaltic pumps, or other similar type pumps known in the art, are used together with inflow and outflow tubing to circulate the cooling fluid. Typically, the cooling system is such that the cooling fluid travels to the probe through inflow tubing that passes through a peristaltic pump head, and returns through outflow tubing that bypasses the peristaltic pump head. Examples devices and apparatuses for thermal treatment of tissues and their operation are described in U.S Patent Application Publication Nos. 20130197504 and 20140207133 and U.S. Pat. Nos. 8,540,710 and 9,084,619, the contents of which are incorporated herein by reference as though set forth in full.
In general, such treatment probes as discussed above fall within one of the following categories: 1) infusion probes, 2) fluid-cooled probes and 3) standard probes (i.e., no cooling/infusion).
Infusion probes introduce saline, or other electrically conductive fluids, into the target site to increase the size of the tissue treatment zone. The infused saline increases tissue conductivity, allowing the energy to propagate farther into the target tissue to provide faster procedure times and larger treatment zones. The saline also minimizes tissue desiccation and charring by conducting energy away from the probe tip where it is most concentrated. This is important since charred and/or desiccated tissue tends to act as an insulator that hinders efficient ablation of the surrounding tissue. Because overheating is generally not an issue with infusion systems, the saline is delivered through a single-lumen tube at a much lower flow rate than required for a fluid-cooled ablation probe. Other infusion devices, such as IRE delivery probes deliver therapeutic agents (e.g., drug-coated nanoparticles, growth factors, etc.) into the target tissue, or require infusion of temperature controlling fluid (such as saline) to prevent unwanted sparking between electrodes that may short out the system and possibly harm the patient.
Fluid-cooled ablation probes include a closed fluid channel through which saline or gas circulates to dissipate heat away from the probe tip where the treatment energy is concentrated. As with infusion probes, the circulating coolant prevents tissue desiccation and/or charring that would interfere with ablation of the target tissue. Since the circulating coolant does not enter the tissue there is no “enhanced conduction” of the treatment energy.
The different flow rates and tubing designs required for infusion and fluid-cooled ablation systems often require specifically designed peristaltic pumps that are not amenable for multi-purpose use. Peristaltic pumps for infusion ablation systems may not be robust enough to support the higher fluid flow rates required for fluid-cooled ablation systems. For example, a typical infusion ablation system may require infusion fluid to be delivered at a flow rate of 0.05-0.7 ml/min, while a typical fluid-cooled ablation system may require coolant to be circulated at a flow rate in excess of 80 ml/min. Additionally, peristaltic pumps for fluid-cooled ablation systems include complex routing paths for inflow vs. outflow tubing, which complicates setup and increases the likelihood of user error.
There is a need for a multi-purpose subassembly that is easy to use, supports all infusion and fluid-cooled ablation systems and readily and reliably accepts a variety of tubing designs to decrease preparation time and minimize user error during setup and use.